The applicant has already proposed such a type of thermochromic coloring color-memory material (see e.g., Patent Document 1).
Conventional reversible thermal discoloration materials discolor with a discoloration temperature as a border. In the material, only one specified state of both states before and after discoloration exists within a normal temperature range, and the other state is maintained while a heat or cold necessary for expressing the state is applied but returns to the state of normal temperature range when application of the heat or cold is removed. In comparison with such a type, the above-described thermochromic coloring color-memory material can selectively maintain, within a normal temperature range, either of the color on the side lower than the discoloration temperature and the color on the side higher than that and can alternately maintain the color by applying a heat or cold as needed. The material is therefore used in various fields such as temperature-sensitive recording materials, toys, ornaments and printing.    Patent Document 1: JP-A-2004-107367